


Marry a Prime

by Spoon888



Series: Two Cons And A Prime [2]
Category: Transformers - All Media Types
Genre: Accidental Marriage, Cultural Differences, Cybertron, M/M, Megatron And Starscream Are Bad At Communicating, Misunderstandings, Multi, Optimus is oblivious, Optimus: "Happy What Now?", Post War AU, Starscream: "Happy Anniversary!", Sticky, Surprise Marriage, Threesome - M/M/M
Language: English
Status: Completed
Published: 2019-08-07
Updated: 2019-08-07
Packaged: 2020-08-11 05:20:15
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,913
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20148292
Author URL: https://archiveofourown.org/users/Spoon888/pseuds/Spoon888
Summary: Optimus Prime has been happily conjunxed to Megatron and Starscream for a year.This comes as something of a surprise to Optimus.





	Marry a Prime

**Author's Note:**

> This is a big Thank You fic for someone who supported me recently. You know who you are!

After the war, Optimus had taken up residence in one of the city's most sought after penthouse apartments, with views of the senate district and the elevated crystal memorial gardens they were building. It was the sort of abode a celebrity or an aristocrat would have have chosen to live in. As far from the rest of the planet as one hundred and ten floors up a skyscraper could get them.

Optimus had decided to hate it before he'd even seen it. But the key-card had been insistently pushed into his palm by a haggard Prowl who -alongside with a hundred other duties he had taken it upon himself to be responsible for- had been helping with the post-war accommodation crisis. Optimus would have preferred to remain aboard the _Ark_, still docked at the edge of the city, like the other thousand or so Cybertronians (neutral and aligned alike) had been forced too.

"It's already been assigned to you." Prowl had walked away so he couldn't return the key. "If you have a grievance you'll have to submit it in writing, like everyone else."

It had made Optimus feel rather foolish, complaining that an apartment felt too grandiose when there were mecha just happy not to be recharging on the rubble-strewn streets.

So he made do, and tried to fill the open space with what measly possessions had survived the war. But the apartment was still high and cold and isolated, and he longed for the community of a warship; the bustle of the mess-hall during the morning refuel and the muffled sound of life from quarter's next door.

He had never been far from a friend, then.

It was all too obvious that his bare, lifeless apartment was a far cry from the home his once enemies had made for themselves.

Megatron and Starscream had managed to brave the literal Pit the emergency accommodation office had become to lay _their_ hands on a newly refurbished apartment, just a mile outside the senate district.

Only it no longer looked new and refurbished, but lived in, homely, used -_trashed_, really, he recalled Megatron once complaining. And had to agree.

Starscream had kept every possession he had ever owned and had managed to cram it into the one bedroom apartment at the cost of ever being able to walk anywhere without knocking down a stack of boxes with his wings, and Megatron didn't appear to know what to do with used energon cubes except to leave them piled up on any available surface. There were fist-shaped holes in their walls and scorch marks across the decking of their balcony, and the light in their wash-room had gone out at _least_ two weeks ago and still hadn't been changed- but at least their chaos was... _them_. It was a mess and so where they and Optimus... _enjoyed_ being there.

His apartment was stale, and he didn't know how that reflected back on him.

But at least he didn't have to spend so much time there anymore. For every night he spent in his own berth, he spent three in Megatron and Starscream's.

Perhaps it was time to reign himself in. Preferably before he became attached.

"Dinner?" Starscream flew by his office to see him, making avoiding their company doubly hard.

"I wouldn't want to impose." Optimus held up a hand to turn down the generous offer. Fuelling became 'facing, and he could never trust himself _not_ to fall into their berth, _not_ to be corralled into staying the night. Again.

"I have a lot of work to get through at any rate," he added. "I've fallen behind on just about everything-"

Starscream kissed his teeth and rolled his optics. "Fine. We'll come to yours. Seven good for you?"

He was winking and slipping out the door before Optimus could respond. "Wait-!" He called after Starscream. "You don't know where I live!?"

It turned out they _did_ know where he lived, which was mildly concerning when considering his address wasn't registered publicly.

At seven thirty -half an hour late, half an hour Optimus had spent wringing his hands together and peering through his floor-to-ceiling length windows to the elevated walkway below for any sign of his guests- the door chime rang.

He swept hands down his front to brush away nonexistent dust and straighten his windshield wipers, and opened the door.

Starscream was over the threshold before it had fully opened, stretching onto his toe-pedes to catch the side of Optimus's mask in a kiss as he passed. "Oh, nice view." He was off to survey the apartment in the next second, speeding down a hallway.

Megatron trudged in after him, rather less enthusiac. "Don't expect a kiss from me." He grunted, optics already searching the apartment. "Why is yours so much bigger...?" he muttered resentfully.

"It's too big, really." Optimus sealed the door behind him and wished he'd done a little more to make his home welcoming; added some colour, some pillows, art on the wall, anything to make it look lived in.

"I think it's just right." Starscream reappeared from the hallway looking satisfied. He shared a look with Megatron and nodded. "Yes. This'll do nicely." He began to wander off in search of the other rooms. "You'll need a bigger berth!" He called from what sounded like the berthroom.

Optimus decided to leave him to it and began to fill cubes from the energon dispenser. He pinched two between his fingers and extended one to Megatron, who took it without a thank you, downed it in one. And then pressed Optimus up against the window with a surety and ease that made his vents stutter.

Optimus retracted his battle-mask on instinct, and Megatron smothered him with a kiss, the taste of fresh energon heavy on his tongue and Starscream's voice in the background giving a running commentary on his tour of the apartment. Tongues twined together and Optimus's back hit the glass with the clink.

"-take down that hideous panelling in the washroom and change the lights and it'll look worlds better!" Starscream's voice grew and faded as he moved between rooms.

"Megatron," Optimus began, turning out of the kiss, clutching Megatron's thick biceps, arching into the mouth now on his neck. He glanced behind, out through window he was flush against. They couldn't be seen from the walkway, but any passing aircraft might-

A leg threaded between his and the top of Megatron's thigh ground up into his codpiece. He jolted and kicked back at the glass. The entire panel shuddered precariously. He didn't know how much weight it could take.

"Urgh!" Starscream's voice screeched through the apartment as they rocked together against the window, fingers fumbling, armour flush. "An _orange_ couch?! Prime, what's _wrong_ with you?!"

"Megatron please." Optimus tried to catch the fingers wandering between his thighs. They dragged across his panel, back and forth, back and forth, until Optimus could resist no longer and let it fold away, moan echoing through the near-empty apartment when rough finger pads rolled over his node and pressed inside.

He was still shamelessly riding Megatron's fingers when Starscream walked back in, tutting at the crimes against interior decorating. He picked up the cube Optimus had never had the chance to consume and began to drink, sitting on the edge of a side table so he could watch Megatron's forearm work, moving with increasing speed he fingered Optimus.

Over Megatron's shoulder, their optics met. Starscream smirked. Megatron curled his fingers. And Optimus's knees gave out as pleasure shot through his pelvis and threw him into an overload, lubricant pooling in Megatron's palm as his fingers continued their fast plunge and retreat, until Optimus's optical feed crossed and his back squeaked against the window as he sank slowly down, legs turned to plasticine.

Ten minutes later the three of them were wedged together on the hideous orange couch Starscream hated, Optimus dazed and slumped in it's centre, head pillowed on Starscream's shoulder, Megatron's arm about his waist, stroking his hip.

"So." Starscream began.

Optimus was still running at half-speed after his overload, so it took him a moment to respond. "...So?"

"I like it. We'll move in tomorrow." Starscream stroked his head.

"Wait," Optimus blinked and began to lift his head. "Moving in? Here?"

Starscream pressed his head back to his shoulder. "Of course. _Our_ apartment's hardly suitable-"

"It's not big enough for three of us." Megatron agreed.

"And this is nicer anyway." Starscream sighed. "...Once it's had work done."

Optimus worked to connect the dots in his processor. "You're moving in with me?"

They seemed to think his question was rhetorical, because he never received an answer. The conversation veered off into weekend plans- plans which he appeared to have a say in, and he forgot all about the proposal of moving in together when he became engrossed in a disagreement with Megatron over whether to see the electrical orchestra at the Iacon Concert Dome or to travel all the way to Nyon to watch the racing.

He won, but only because Starscream flicked Megatron in the back of the head and said if he had to 'watch one more blasted go-karting race' he was going to stick needles in his optics.

Megatron traipsed off, sulking, but Optimus hardly noticed his absence when he and Starscream became carried away reminiscing over memories of the old Iaconian Concert Hall. Orion Pax had once sat on the curb outside with Ariel, straining their audials to catch the tune through the hall's thick walls.

Starscream had also visited. Once.

And promptly blown it up.

"That was _you_?" His head had fallen into Starscream's lap by now. He looked up at the seeker with a mix of awe and horror.

Starscream stared off into the distance, clever mouth curved. "You'd be hard pressed to find an attack I didn't have a hand in."

It was past midnight (and Optimus would regret not retiring sooner in the morning when it was time to rouse himself for the office) when they finally fell into the berth together, Starscream tackling him to the sheets and assaulting him with kisses. Half the berth was already occupied by Megatron, snoring into Optimus's pillow as if it was his own, so Optimus did his best to curb his enthusiasm.

He folded his mask back and shoved his fist into his mouth, biting down on grunts and groans as Starscream's spike pressed into him, distracted by the slumbering giant beside them.

"He's slept through emergency klaxons. He _won't_ wake up." Starscream prised his hand away from his mouth and told him, pinning his wrists beside his head so he _couldn't_ muffle himself.

Then he snapped his hips forward and hit the spot inside Optimus that had him seeing stars. Optimus shouted a curse, and had to concede, when Megatron continued to snore like a broken chainsaw, that Starscream was right.

* * *

Optimus had no idea how he had coped living alone. Nor how he had managed to adapt to his new roommates.

_Now_, there was never a moment to himself or a pause in the noise. He couldn't sit down without a pair of legs getting thrown into his lap or arms manhandling him into an embrace. No matter how often he picked up after his roommates, there was always another mess being created elsewhere. He never fuelled alone, there was never hot solvent for his showers, and his berth was always overcrowded.

And though the two Decepticons' presences in his home had come with great inconveniences, Optimus appreciated them all the same, just because they were there.

After a long _long_ day debating planetary defence and if a unified Cybertronian military was even possible, Optimus had been dreading work's inevitable continuation in his home-office. There were max-memory datapads stuffed full of meeting notes to go over yet, endless bureaucracy that begot yet more bureaucracy.

But he stepped through the front door into the dumping ground his living room had become over the last few weeks, and felt... _relief_. The holo-screen was playing away to an empty room at full volume and the shower in the washroom was running, both of which Megatron and Starscream appeared to be shouting over the top of from different rooms.

"-working fine when I used it!" Starscream's voice yelled from the washroom's open doorway, steam billowing out in to the corridor.

"Blasted machine!" Megatron snarled and kicked the fuel dispenser he had been battling until it sparked and started smoking.

"You've broken it." Optimus murmured, watching the large grey mech shake it with vigour.

Megatron looked up. "He's home!" He shouted in the direction of the washroom.

The tap squeaked and the solvent shut off, and not two seconds later a dripping Starscream appeared, a towel drapped over his wings. "Good. Let's go out."

"Out." Optimus murmured, only just home and bogged down with work he'd do just about _anything_ to get out of.

"For fuel." Megatron gave the dispenser a parting kick and whipped the towel off Starscream's wings. "The dispenser's broken."

"Yes." Optimus glanced at the mess Megatron had made of it. "I can _see_ that."

He had to wait for Megatron to dry Starscream off, and the argument the rushed action produced when Megatron was too rough with the towel, fluffing Starscream's plating and leaving him rubbing sore wings. But then they were off, out the apartment and strolling along the walkway together. In full public view.

Optics followed the unlikely threesome with interest. Optimus was unsure how obvious he should make it that they were with him in a personal sense, and not on their way to some awkward policy meeting, but reaching out and taking Megatron's hand seemed too bold. He settled for letting their shoulders brush, avoiding Megatron's gaze when he felt fingers bump the back of his hand.

All doubt was removed from the bystanders' processors anyway when they arrived at the bar, Megatron stepping aside to let him and Starscream pass through first with a show of rarely witnessed manners, following Optimus in with a hand on the small of his back to guide him. Optimus thought he saw the flash of a camera, but when he glanced up the media drones were already shooting off into the sky with their quarry.

"Is this a date?" He murmured, sat at a small circular low-lit table, fuel in impractically fancy glasses, his legs brushing theirs under the table.

The two Decepticons shared a glance.

"Sure." Starscream shrugged, then plucked a mercury dipped turbo-berry out of the bowl and held it up to Optimus's mask. "Open."

He did, retracting the mask, but before he could eat the treat from Starscream's fingers it was withdrawn and Starscream was leaning over the table to kiss him.

Optimus hummed into it, cracking an optic open to gauge the room, and the mecha doing their level best to pretend they hadn't seen. He drew back, unsure.

"Perhaps we shouldn't-"

A hand gripped the frame of his chair and dragged it across the floor, closer to Megatron. The scrape of the legs against the tile drew the attention of the quiet tranquil room, but Optimus couldn't hold up his hands in a plea for discretion before Megatron had their chairs right up alongside each other and a long arm slung over the back of his seat. He kissed Optimus's shoulder and took a bite of his own mercury dipped turbo-berry, before extending the remains to Optimus.

Optimus opened his mouth, and with seductive savouring speed, Megatron pushed it past his lips, letting Optimus's tongue flick out against his thumb. He had barely chewed before they were kissing again, this time heedless of the audience. He un-shuttered his optics to see Starscream strike a pose through the window as another flash went off, and realised this shameless display was a game for the nosy cameras.

Megatron's fingers brushed the underside of his chin as they kissed, tongues twined and rolling, and Optimus couldn't bring himself to care.

* * *

  
"Nice headlines." Ratchet grunted, thumb on the remote flicking through the holo-screen channels at speed, frowning as every news station played the same story. "What's a mech got to do to get the Cyber-Bowl scores these days?"

Optimus rubbed his aching helm, unsure if the headache he was suffering was the fault of the high-grade he'd consumed last night or the fault of the news stories that had been fuelled by his loss of inhibitions.

Every channel change brought up a new and mortifyingly _telling_ image capture of him at the bar, mask off, cheeks flushed, hands everywhere they should not have been.

"It's not an affair." He grunted as a panel of 'experts' considered the 'evidence' and spoke condemningly about the nature of the Prime's relationship with former Decepticon High Command and what that meant for politics.

"'Hide' says they've _moved in_ with you." Ratchet wasn't taking any prisoners today.

"Their apartment was impractical and I was-" Optimus stopped him self from saying 'lonely'. "They are roommates. Nothing more."

"I used to room with First Aid." Ratchet muttered. "But you'd never catch me in his lap."

Optimus dared to look up, at the picture they'd managed to get of Starscream perched on his thigh, looking up at him coyly.

"It's Starscream." He said, hoping that explained enough, as though the former Air Commander would sit in _anyone's_ lap and let them fondle his cockpit.

Ratchet '_hrmed_'. "You would tell me if it was serious, wouldn't you?"

"You disapprove?" Optimus felt his tank drop.

"Are you happy?" Ratchet turned right around in his chair to face him, looking thoughtful, but worried.

Optimus thought for a moment, of the chaos and unpredictability Starscream and Megatron had brought into his life, of their mess and destructive tendencies, of the fact that he'd never be able to keep anything nice for fear it would be broken, of cold showers and noisy evenings. Of how easy it had been to adapt to their presence, and how eager they were to spend time with him.

He found himself smiling behind the battle-mask. "I am."

* * *

There was a solution to the cold shower dilemma Optimus had failed to consider, until half-awake and bleary optic'd he stumbled into the washroom one morning to find the facilities already occupied.

"Sorry-!" He grunted on instinct, averting his gaze from the sudsy seeker under the solvent and backtracking out of the room again.

"Don't be stupid," Starscream used his lightning fast reflexes to snag a windshield wiper and haul him back in again. "There's plenty room."

There wasn't really. Starscream couldn't turn without smacking him with a wing and they had to take turn's rinsing under the stream, but it was the first warm shower Optimus had in weeks and it was bliss between his seams. Tension drained out of him, soothing aches he hadn't realised he'd been suffering.

Starscream finished before him, but lingered to help finish up, taking the washcloth out of his hand and dropping to his knees, rubbing it in circles over his thighs. Optimus leant against the wall and shuttered his optics, pedes stepping apart when Starscream's explored the seams of his inner thighs, moving up and up.

A hand cupped his codpiece and massaged with the washcloth in the guise of cleaning him, but Optimus knew better, retracting the armour and letting his spike spring free, reaching up to cup the back of Starscream's head when the seeker licked the underside of his spike, from base to tip, then sucked it into his mouth.

He lost himself to the suction of Starscream's mouth, the bob of his head, the building pressure between his hips, and didn't notice a second presence until Starscream was pulling off his spike with a whine and hissing at Megatron that there wasn't room.

Dazed, Optimus watched as there was a brief scuffle, elbows banging the walls of the shower as they all rearranged themselves, Starscream still on his knees and Optimus still trapped against the wall as Megatron inserted himself between them. Then his spike was easing back in tight warm heat again, Megatron's valve this time as the grey mech bent in front of him and backed himself up onto it.

Optimus took his hips and hauled him the rest of the way in one smooth tug, Megatron's aft tapping flush to his hips, spike hilt deep in twitching mesh. Megatron threw out his arms and caught himself against the shower walls, Starscream on his knees tonguing at Megatron's codpiece to tease his spike out as they all began to move as one.

It was a _great_ improvement on cold showers. 

* * *

Megatron hadn't worn his fusion cannon since peace had become official. Starscream too, over the months as he adapted to civilian life, had taken breaks in wearing his null-rays, though Optimus couldn't remember the last time he'd seen Starscream with them on.

To Optimus, it appeared they had moved on with relative ease. Easier than he had. 

"You don't need this anymore." Starscream cooed, draped over him to stop him escaping, fingers in his jaw seams searching for the mask release. Optimus craned his neck away, hesitant to let him.

"C'mon Prime, don't be coy," Starscream smiled. "Let me see your handsome face-"

"Just rip it off." Megatron grunted from his armchair with a surety that told of his experience in such matters, watching them roll about on the sofa.

"I'm not _maiming_ him." Starscream muttered. "That's what I have you for."

"It's fine. I'll release it." Optimus conceded, brushing searching hands away and sitting up, dislodging Starscream from his chest and sending the seeker sliding into his lap.

"Remove it." Starscream corrected. "You don't need a battle-mask. And it's going to start sending people the wrong message. What do you think is going to happen anyway, that we'll attack you in your sleep?"

They regularly did, Optimus thought to himself privately, thinking of all the times wandering hands and mouths had roused him from recharge. "It's not you." He reassured them. "Simply... habit."

"Being able to hide, you mean?" Starscream said cleverly.

They were looking at him expectantly, so Optimus decided he'd better get it over with, unlatching the plate from his face completely and gently working it free. He pulled it away from his face, feeling bare and exposed, but Starscream was pressing lips to the smoother derma underneath the very next second, humming happily.

"Can't fault it's effectiveness." He purred, rubbing their cheeks together like an affectionate cyber-cat. He took the plate out of Optimus's lax fingers, and tossed it to Megatron.

Megatron promptly snapped it in half.

Optimus stared at the two halves, feeling a sense of finality, not sure he liked it, not sure if he was ready for the planet to see him without it, to see him as he was, just as out of depth with this new world as they all were.

"Much better." Starscream took his face and titled it up to the light. "Isn't it, Megatron?"

Megatron grunted with disinterest, but that night in berth together, a mess of limbs and hot desperate frames, Megatron couldn't take his optics off him.

* * *

"Here."

Optimus looked up when Starscream laid a stack of datapads down on of his home-office desk. For a dreadful moment Optimus feared it was more work that had been sent home to him from the senate, before he glanced at the title of the first file.

"Poetry?" He murmured.

"For Megatron's creation day." Starscream shrugged, looking disgusted with himself. "He never tells me what he wants so I have to guess. It was either these," he pointed a sharp digit at the files, "Or tying little bows around our spikes and lounging seductively in berth, waiting for him to come home."

Optimus wanted to point out that _his_ bow would need to _big_, actually, but he had a slightly more pressing question first.

"It's _Megatron's creation day_?!" He breathed, awed.

"No," Starscream pulled a face. "But I don't know when it is, and neither does Soundwave. So I just pick a date and force a gift on him anyway."

"Oh," Optimus, somehow, found it very believable that Megatron would keep the date of his creation a secret. Nothing about Megatron implied he wanted people making a fuss of him.

He looked at the poetry thoughtfully, stroking his chin.

"Why don't we do both?"

A grin split Starscream's face. He brought a roll of silky red ribbon out from behind his back. "I was hoping you would say that."

* * *

Optimus's office hours felt longer and longer with each passing day.

The pettiness of his work load only worsened as the more pressing issues of society were dealt with (trials, law, infrastructure), and the menial, but no less essential aspects were left for 'later'.

'Later' was unfortunately _now_.

That he spent three hours in a meeting about planetary traffic law did not help his longing for home either, to sit on the couch, switch off his processor, and do nothing. He had never been one for long weekends spent doing nothing- until he'd had someone to do nothing with.

He just was highlighting passages of Ultra Magnus's magnum opus on traffic regulations when his regular lunch dates came bickering into his office. It seemed early, so he checked his chrono, unwilling to believe time could pass so quickly when doing such processor numbing work.

"It's too early for lunch." He told them, but wasn't sure they heard him over their own argument.

"-short cut my aft! You make us go the long way around every _single_ time because you like looking at the Hound's garden outside the court house-!"

"The crystal-poppies are in _bloom_, Starscream!" Megatron argued back, unashamed.

"Sorry we're _late_!" Starscream told Optimus, but was still glaring at Megatron. "_Someone_ here was composing a dissertation on the '_passage of light through pink petals_'-"

"You're not late." Optimus hoped to soothe them before they had an argument over nothing and ruined the one precious hour they had together before the long slog to the end of the day. "Most bars aren't even open-"

"We know how to tell time, Prime." Megatron cleared Optimus's deck of Ultra Magnus's files, knocking them to the floor and out of order. It would take hours to re-sort. "We're not here to fuel."

"We're here to interface." Starscream filled in, and Megatron lifted Starscream by the waist and hoisted him up on to Optimus's cleared desk. Starscream swung around on his aft to face Optimus, dropping heeled thrusters to Optimus's armrests and caging him in.

Optimus blanched. "_Here_?"

"Why not?" Starscream shrugged, leaning back on his hands as Megatron stood behind him and began kissing his neck, along his wings. He opened his panel and let his thighs fall wider, showing himself off. He arched back against Megatron, valve mesh parting to reveal his little node and dampening folds. "You can watch, if you don't want to join in?"

Like Pit was he _just_ watching. 

Battle-mask gone, Optimus could take Starscream's knees in each hand, push thighs open to breaking point, and drop his face straight into the apex of glossy white thighs. A moan warbled out of Starscream and he fell to lie across the desk, head thrown back and claws carving as Megatron began to unlatch his codpiece.

Optimus rolled his tongue through Starscream's folds and watched Megatron guide his spike to Starscream's intake, rubbing the tip over parted lips before feeding it into the seeker's mouth. Callipers clenched around Optimus's tongue as Starscream's moans became garbled and his throat worked. The office filled with huffing vents and slick noises, hopefully just quiet enough not to attract the attention of his secretary drone.

Or Prowl, diligently working next door.

* * *

He was woken with a kiss some weeks later, so used to them now that he could tell -even with a processor full of fuzzy dreams- which of his Decepticon roommates it was. The smell, the pressure, the press of a tongue to his own.

_Hmm_, he thought, sleepy and stated from a good night, _Megatron_.

Starscream was still asleep, he could tell from the speed of the vents of the seeker lying half under him, an arm looped around Optimus's back, cockpit glass a smooth, cool texture against his cheek.

He felt Megatron move away from his mouth and kiss Starscream's glass next, and he rolled aside to give him the room to trail kisses up Starscream's front. He heard some grumpy morning complaints -Starscream was never in a good mood before noon- and a mutter of, "Happy anniversary to you too".

A special date for them, it seemed. He would have to get them a present, he reminded himself, rolling further onto his side, away from the enamoured couple. He heard the smack of lips on lips grow in enthusiasm as they roused further, and the hollow feeling in his chest decided to make itself known.

He rolled out of bed before his jealousy could ruin their mood, heading for the safety of a shower.

"Optimus?" He heard Starscream call from the berth, but was far enough into the washroom to pretend he hadn't heard, switching on the shower and standing under the cold solvent, not bothering to wait for it too heat.

When he came out, dry and gleaming, they were still at it, pressing one another back against the walls on their way to the dispensary. Optimus grabbed a quick cube-to-go in hopes he could slip out of the apartment and be on his way to the office without them realising, but he had only just lifted the cube when thick, strong arms wrapped around his middle, tight. Inescapable.

"Where do you keep wandering off to?" Megatron purred.

Optimus leant away from the kiss to his neck, gently pushing at Megatron's arm. "I should be on my way. I can't be late-"

He heard as much as felt Megatron's frown on the back of his neck. "You're not going to work today."

Optimus opened his mouth to ask why when Starscream reappeared. He rather hoped Megatron's attention would be retaken by the seeker, but it wasn't to be. Megatron held tight, lifting Optimus's pedes off the ground as he swung him around to face Starscream.

"Happy anniversary," Starscream looked aside, uncharacteristically shy as he extended the small gold box sat in the centre of his palm.

Optimus glanced at Megatron, waiting for him to take it. Megatron frowned down at him, and gave him an insistent little squeeze. Optimus looked at Starscream next, still holding the box, frowning.

"What?"

"It's for _you_." Starscream snapped, looked annoyed. He shook the box. Something small and heavy inside shook about.

"Me?!" Optimus felt Megatron's arms finally relax from his middle, hands falling instead to his hips. "But it's not my..."

Megatron and Starscream stared at him. He stared back, looking between them, optics growing wider with each pass between them.

"...Anniversary of what?" He began cautiously, wondering if perhaps it was to commemorate them living together, though that had been far longer than a year-

"Are you _stupid_?!" Starscream burst out, angry now. "It's our first anniversary! You forgot?!"

"_You_ forgot until I reminded you yesterday." Megatron leant over Optimus's shoulder to murmur to at the seeker.

"Well you clearly didn't remind _him_." Starscream pointed at Optimus.

"I must think too highly of his memory capabilities." Megatron sounded disappointed.

Prime pushed Megatron off his hips, moving out from between the two Decepticons, "Anniversary... of _what_?!"

"Our conjunxing!" Megatron and Starscream answered as a chorus.

"Your conjunxing?" Optimus pointed between them.

"No!" Starscream stamped a foot, teeth clenched. "_Our_!" He swung his finger in a big circle to indicate all of them. _All_. Of. Them. "Our anniversary. The three of us. _You_ and _us_!"

This was certainly news to Optimus. "We're not conjunxed!" He exclaimed. "We- when?! When did- we're-"

"We've been _living together_ over a year." Megatron pointed out, looking at him like he as an idiot.

"We've been interfacing for _two years_!" Starscream was _by far_ the least calm of the three of them, purple in the face. "Of course we're conjunxed. You think we do _that_ with just anyone?"

"It-" Optimus was stumbling over his words worse than he had when he'd given his first speech as Prime. "That was- that was a casual arrangement, for your creation day-"

"And we invited you back!" Starscream argued, talking fast and sharp. "Again and again and again and then we _moved in with you_!"

"There was no ceremony-" Optimus floundered, trying to think back to an occasion he might have _forgotten_ in which he stood in front of witnesses and spoke vows and sighed a contract and-

"A _ceremony?!"_ Megatron looked disgusted.

"You Autobots still _do_ that?!" Starscream's optics flared. "What is this? The prehistoric age?! We're conjunxed because we _live together_, you idiot! Because we _love you_! Who the Pit needs a ceremony to legitimise that?!"

"How long have we been conjunxed?!" Optimus felt somewhat hysterical.

"A _**year**_!" Starscream bellowed at him, losing what little remained of his cool. "Because it's our _fragging anniversary_!"

* * *

"We don't have to be conjunxed." Megatron told him some hours later, when things had calmed down.

Starscream had gone for a flight and was yet to return, but Megatron assured him he would. He was likely in Vos, venting to his trine. Megatron himself had taken the misunderstanding better -after staring out the window for some time with a worryingly blank look on his face. Optimus just felt guilty and foolish. Should he have noticed? How had he not? Why hadn't they just _talked_ to one another about this?

But given time to collect their thoughts, both he and Megatron had come to the realisation that four million years of war had left them all with a rather large cultural gap.

"No." Optimus said immediately. They were in berth together, lying side-by-side on their backs. "I want to be your conjunx. And Starscream's. I just... expected a ceremony."

Megatron made understanding noise.

Optimus continued to stare at the ceiling. "I've had two conjunxs for over a year and I never realised." He mumbled. Then sat up, shocked. "And you _love_ me."

Megatron looked grumpy, "_Starscream_ said that."

"You don't feel the same way?" Optimus arched a brow.

Megatron snorted, "Don't start with me. You didn't even know we were an item."

"I love you." Optimus settled back down against his shoulder, spooning him from the side. "I love Starscream."

"I'd wait a few hours to tell him." Megatron advised. "And perhaps buy him a few gifts."

"Noted."

"You can have a ceremony, if that's what you need." Megatron said after a pause. "You Autobots and your _traditions_-"

"Thank you." Optimus smiled, "But Starscream was right. We don't need ceremony to prove our love."

Megatron's arm finally came around his back, a reluctant smile pulling at his lips as he tugged him closer. "You're an idiot, Prime."

"So are you, Megatron."

Starscream returned from his 'flight' some three hours later, smelling of ozone and an expensive brand of Vosian solvent his trine used, and slipped into the berth with them. Optimus heard him huff against his audial.

"I love you." He muttered into the darkness, between Megatron's rumbling snores.

There was haughty sniff. "You're lucky you're cute." And arms wrapped around his middle.

And laid between his mates, his _conjunx enduras_, Optimus had his best nights sleep yet.


End file.
